Revert "Fix Head params to accept classifier_activation"

This reverts commit 00d4889.

Author: Frightera

keras/applications/regnet.py

@@ -833,12 +833,11 @@ def apply(inputs):
     return apply
 
 
-def Head(num_classes=1000, classifier_activation=None, name=None):
+def Head(num_classes=1000, name=None):
     """Implementation of classification head of RegNet.
 
     Args:
       num_classes: number of classes for Dense layer
-      classifier_activation: activation function for the Dense layer
       name: name prefix
 
     Returns:
@@ -849,11 +848,7 @@ def Head(num_classes=1000, classifier_activation=None, name=None):
 
     def apply(x):
         x = layers.GlobalAveragePooling2D(name=name + "_head_gap")(x)
-        x = layers.Dense(
-            num_classes,
-            activation=classifier_activation,
-            name=name + "head_dense",
-        )(x)
+        x = layers.Dense(num_classes, name=name + "head_dense")(x)
         return x
 
     return apply
@@ -982,12 +977,8 @@ def RegNet(
         in_channels = out_channels
 
     if include_top:
+        x = Head(num_classes=classes)(x)
         imagenet_utils.validate_activation(classifier_activation, weights)
-        x = Head(
-            num_classes=classes,
-            classifier_activation=classifier_activation,
-            name=model_name,
-        )(x)
 
     else:
         if pooling == "avg":